A ground-breaking clinical trial for women diagnosed with stage IV metastatic breast cancer is now enrolling patients at the University of Virginia Health System.

The pilot study combines two therapies: focused ultrasound and a cancer immunotherapy drug. Patients in the clinical trial will receive non-invasive focused ultrasound therapy to ablate (or destroy) part of the primary breast tumor or metastatic tumors along with administration of the Merck medication pembrolizumab (Keytruda®). The highly accurate focused ultrasound treatment will be delivered using Theraclion’s EchoPulse system. Fifteen women will be enrolled in the study.

The clinical trial is being led by Patrick Dillon, MD, Associate Professor of Hematology and Oncology, and David Brenin, MD, FACS, Associate Professor of Surgery and Chief of Breast Surgery. “The immune system does not recognize most breast cancers as invading or foreign cells, so the body does not mount an immune response against it,” said Dr. Brenin. "Focused ultrasound induces a local immune response and may have the ability to change that paradigm, enabling a medication like pembrolizumab to make a difference.”

Dr. Dillon adds, “Currently women with metastatic breast cancer have to deal with lifelong treatments such as chemotherapy or anti-estrogen therapy that impart toxicity on recipients. It is hoped that immune therapies might have less toxicity and shorter-term use.”

Preclinical studies have suggested that focused ultrasound can “unmask” breast cancer cells, making them visible to the immune system. The theory is that applying focused ultrasound to the tumor creates a local immune response that draws anti-cancer immune cells to the area. The pembrolizumab could then prevent the tumor cells from deactivating the invading immune cells, allowing the immune cells to continue killing cancerous cells.

Funding for the trial was provided in part by the Focused Ultrasound Foundation and the Commonwealth of Virginia. “Cancer immunotherapy has emerged in recent years as one of the most promising areas of medicine, and one of the Foundation's central initiatives is dedicated to exploring how focused ultrasound can enhance its effects,” said Foundation chairman Neal F. Kassell, MD. “This is the first time these therapies are being used in combination in patients, and we are proud to support this innovative trial.”

EchoPulse is designed to non-invasively ablate breast tumors using real-time ultrasound guidance. Although it is not yet approved by the US Food and Drug Administration, the system received the European CE Mark in 2012, where it is used to treat breast fibroadenomas, thyroid nodules, and other conditions. Pembrolizumab is not FDA approved for the treatment of breast cancer and is considered investigational for the purposes of this study.

Why does Dr. Brenin think that combining two therapies that do not successfully treat breast cancer alone might work? Listen to him describe the mechanism in a recent Theraclion webinar. Learn more details for patient inclusion and exclusion on clinicaltrials.gov, and read additional coverage at MedicalPhysicsWeb.